A simulation study on the effect of the “bull’s eye” in ductile iron on stress concentrations was done in this work. Using the model of graphite nodules in a cavity, a two dimensional plate strip was subjected to plane stress conditions. The results were compared to the traditional theory of modeling the graphite as holes (cavity) in the iron matrix. In plane stress conditions, while the graphite in the hole model showed the hole as areas of stress concentration and therefore very critical as regards fracture, the hole model showed stress concentrated away from the holes making the holes not very critical factor as regards fracture. It was observed that areas of stress application were more critical than the voids when using the hole model. Also the graphite in the hole model was able to predict the good damping behaviour of ductile iron and the increasing elongation with decreasing nodule count.

Supply chain finance is an efficient method to solve SME’s financing problem. A core issue is to simulate the supply chain finance system’s real operations. To solve the problem, this paper designs a simulation model for supply chain finance based on Simon’s bounded rationality with multiagent simulation technique instead of absolute rationality. The influences of the behaviors of bank, SME and warehousing company on credit risk of the supply chain finance are simulated and managerial insights are given. The research can help to reduce credit risk of bank loan while increasing the supply chain system’s benefit.

Berger, A.N. and Asli, D.K. (2004) Bank Concentration and Conference: An Evolution in the Making a Conference Sponsored by the Federal Reserve Bank of Cleveland. Journal of Money, 6, 433-451. http://dx.doi.org/10.1353/mcb.2004.0040

This research effort compares four sequencing rules intended to smooth production scheduling for mixed-model production systems in a Just-in-Time/Lean manufacturing environment (“JIT” hereafter). Each rule intends to schedule mixed-model production in such a way that manufacturing flexibility is optimized in terms of system utilization, units completed, average in-process inventory, average queue length, and average waiting time. A simulation experiment, where the various sequencing rules are tested against each other in terms of the above production measures, shows that three of the sequencing rules essentially offer the same performance, whereas one of them shows more variation.

Objective: It is important and helpful for surgeons to understand the correlation between spinal anatomy and screw trajectory before surgery. We aimed to assess a simple technique using 3D imaging software available on the hospital intranet for visual and quantitative feedback to prepare surgeons for an appropriate entry point and safe trajectory when placing cervical screws. Methods: A total of 59 cervical screws were inserted from C1 to T1 in 12 consecutive patients using this technique. First, a single CT optimal slice was selected from 3D CT images of the cervical spine to determine the intervals of bilateral entry points and lateral angle. Next, this 3D image was rotated to the lateral angle. Finally, bone was cut out on the entry point using subtractive manipulation, which removed the core of the pedicle or lateral mass. Screw trajectory was indicated, and surgeons could assess the correlation between surface landmarks, spinal anatomy, and screw trajectory. Posterior cervical fusion was performed using fluoroscopy. Postoperative outcomes and incidence of complications were retrospectively assessed. Results: One perforation (1.4%) was identified on postoperative CT images. No vascular injuries occurred. Differences in the intended entry point location and lateral angle of the screw from actual postoperative values were 1.49 ± 1.23 mm and 5.46。 ± 4.46。, respectively. Conclusions: A novel 3D CT imaging assessment underwent in cervical screw fixation. This technique is easily accessible on the hospital intranet and provides training in cervical screw placement for fellows. Surgeons can simulate screw placement and share surgical strategy.

In brake systems, where the components are exposed to mechanical and thermal loads, the numerical analysis is very helpful. The main function of the brake system is to control or reduce vehicle’s speed by transformation of kinetic and potential energy in thermal energy. Using finite element method and Abaqus application, the present work proposed a model to study the impact of these loads on the performance of a pneumatic S cam drum brake’s friction material. The model included the effects of the rivet process; brake torque and warming in one of the 17 t bus front brake lining. Areas where the stresses vary with considerable amplitudes during temperature increase and brake application were identified. Also, it was possible to compare results of the numerical model to vehicle’s experimental measurements and understand its proximity to real braking events. By the application of the methodology and using the numerical model, proposed in this work, it will be possible to contribute considerably for a more accurate design of the friction material, besides undertake a better selection of the sub-compounds which it is made of.

This paper highlights the benefits of using intelligent model based controllers to produce FES induced sit-to-stand movement (FES-STS), in terms of reducing energy cost and producing more natural responses in comparison with conventional controllers. A muscle energy expenditure model for the quadriceps is implemented in the control design of FES-STS, then simulation is run for three different control designs: an adaptive neuro-fuzzy inference system controller (ANFIS), a conventional PID controller, and a hybrid ANFIS-PID controller. The PID control strategy results in negative energy expenditure of the quadriceps at the end of the STS initiation phase, this negative energy is caused by the high lengthening speeds at the muscle fiber level, which may lead to muscle fatigue or damage. Contrary to PID controller, model based controllers show positive energy expenditure, lower energy costs, and more natural curves of energy expenditure and knee torques.

Hamid, S. and Hayek, R. (2008) Role of Electrical Stimulation for Rehabilitation and Regeneration after Spinal Cord Injury: An Overview. European Spine Journal, 17, 1256-1269.http://dx.doi.org/10.1007/s00586-008-0729-3

I describe a method for the observation of Positronium (Ps) involvement in the solar radiation spectrum. In this method, Rydberg-Ritz’s principle and Planck’s radiation formula are used to acquire information of the atomic transitions of Ps alike Hydrogen and Helium. In order to perform this experiment, an advanced solar spectrum monitor is constructed by utilizing light emitting diodes (LED) of various colors. A detailed study on this method provides qualitative agreement with experimental data, giving insight to the physical process involved in the solar radiation spectrum and confirming the existence of solar Ps.

Puxley, P.J. and Skinner, C.K. (1996) A Search for Infrared Positronium Line Emission from the Great Annihilator near the Galactic Centre. Proceedings of the Galactic Center, 4th ESO/CTIO Workshop, La Serena, 10-15 March 1996, 439.